Ceratophyllum

Rough Hornwort ( Ceratophyllum demersum )

Hornwort ( Ceratophyllum ), sometimes misleading referred to as chickweed ( this is already the German name of the genus Cerastium ), is the only plant genus of the family of Horn -leaved plants ( Ceratophyllaceae ) and the order of the horn sheet -like ( Ceratophyllales ) within the angiosperms ( Magnoliopsida ). The genus name is from the Greek words Ceratophyllum ceratos for Horn and phyllon derived for sheet. These aquatic plants are not to be confused with the sometimes quite similar looking stoneworts.

  • 5.1 Notes and references

Description

Ceratophyllum species consist of a central stem axis with a high tensile strength, but fragile stems, are attached to the leaves and lateral axes. The major axis to a length of about 1 meter. Ceratophyllum species have no roots to anchor the soil. They float freely in the water and absorb nutrients through root-like structures that can be created from converted sprouts. The plant grows at one end on, while it dies at the other end.

The leaves are composed of whorls ( whorls ) and forked once or multiple times depending on the type. When frequent Rauen Hornwort example, they are one to two times forked, dark green and end in two to four rigid, harsh, linealischen corners. In rarer Delicate epidermis they are lighter green, fine and three to four times forked with five to eight corners.

The hornwort species are dioecious getrenntgeschlechtig ( dioecious ). The very inconspicuous flowers are in the leaf axils, but are scarcely observed. Also, fertilization and seed formation occur under water.

In general, the spread of the plant, however, takes place vegetatively by the brittle stem axis decompose in the spring. For each fragment of a new individual grows up. In addition, in the fall of starch-rich winter buds ( turion ) are formed, which become detached and fall to the ground. Out of them arise in spring also new plants.

Occurrence

The genus Ceratophyllum is represented worldwide with about ten species in freshwater. Ceratophyllum species grow in stagnant or slow-flowing, summer warm, nutrient-rich, often even hypertrophic ( polluted ) waters.

System

The species of this family are very different from all other flowering plants. They are probably the sister group of the Eudikotyledonen, but possibly also of monocots or Chloranthaceae.

The genus Ceratophyllum was erected in 1753 by Carolus Linnaeus in Species Plantarum.

Species

There are about six ( or ten ) species in the genus Ceratophyllum:

  • Rough Hornwort ( Ceratophyllum demersum L.); Home: Europe, North Africa, Asia.
  • Ceratophyllum echinatum A. Gray
  • Ceratophyllum muricatum Cham.
  • Broad Prickly hornwort ( Ceratophyllum platycanthum Cham. )
  • Tender Hornwort ( Ceratophyllum submersum L.); Home: Europe, North Africa, Asia.
  • Ceratophyllum tanaiticum Sapjegin

Hunting and

In the hunting and find various types of leaves using horn. They are characterized by strong growth and help improve water quality. Your ability to absorb dissolved nutrients in the water, they can also appear suitable for algae control.

Swell

  • The order of Ceratophyllales in APWebsite. (English )
  • Description DELTA.
  • Walter Erhardt, Erich Götz, Nils Boedeker, Siegmund Seybold: The big walleye. Encyclopedia of plant names. Band. 2 species and varieties. Eugen Ulmer, Stuttgart 2008, ISBN 978-3-8001-5406-7.
Angiosperm Phylogeny Group
173213
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